osxkeychain: use go build constraint

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

osxkeychain/cmd/main.go

@@ -1,3 +1,5 @@
+//go:build darwin && cgo
+
 package main
 
 import (

osxkeychain/osxkeychain.c

@@ -1,4 +1,4 @@
-#include "osxkeychain_darwin.h"
+#include "osxkeychain.h"
 #include <CoreFoundation/CoreFoundation.h>
 #include <Foundation/NSValue.h>
 #include <stdio.h>

osxkeychain/osxkeychain.go

@@ -1,10 +1,12 @@
+//go:build darwin && cgo
+
 package osxkeychain
 
 /*
 #cgo CFLAGS: -x objective-c
 #cgo LDFLAGS: -framework Security -framework Foundation
 
-#include "osxkeychain_darwin.h"
+#include "osxkeychain.h"
 #include <stdlib.h>
 */
 import "C"

osxkeychain/osxkeychain_test.go

@@ -1,3 +1,5 @@
+//go:build darwin && cgo
+
 package osxkeychain
 
 import (